LECTURE 5 Tobacco&Marijuana

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LECTURE 5

TOBACCO &

MARIJUANA

28th January 2014

Giorgia Pastorin

[email protected]

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Before

T/F

After

T/F

How much do you know about Tobacco, Marijuana and

prevention programs?

3. SENSITIZATION is the opposite of Tolerance

5. A GATEWAY drug is a substance that induces the

individual to isolate him/herself from the society

6. Marijuana determines memory loss, especially among

the young

7. Marijuana’s legalization influences its use, which might

be significantly decreased

8. Marijuana increases violent behavior

9. With drugs of abuse the benefit-cost ratio decreases

10. “Preventive” programs should be organized only for

those who have never taken addictive drugs

11. Preventive Programs are more effective if performed by

peers rather than police officers (for the young)

1. With smokeless tobacco, there is a lower probability to cause lung cancer but higher risk for mouth cancer

2. Smoking during pregnancy seems to determine smaller

head circumference in the fetus

4. Marijuana is highly addictive

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Tobacco

Nicotine

Psycho-

Therapeutics Prozac

Haloperidol

Opioids Morphine

Codeine

Heroin

Methadone

Depressants Barbiturates

Inhalants

Alcohol

Marijuana

Hallucinogens

LSD

Stimulants Cocaine

Amphetamine

Caffeine

Psycho-

active

Drugs

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TOBACCO

One of the greatest social Dilemma.

<< It is the most avoidable cause of death in

our society>>

Introduced in Europe in 1529, as “Holy

Plant”

Its active ingredient, NICOTINE, was

isolated only in 1828

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Mortality ratios (total death, mean age 55 to 64) as a

function of the age at which smoking started and the

number of cigarettes smoked per day.

Drugs, society and human behavior, McGraw-Hill Education, 2009, page 244

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…more adults?

…more sexy/macho? …more alert?

Why? To seem…

- Pleasure

- Curiosity

- Enhanced

performance

- Sensation seeking

- Peer pressure

- Rebellion against

parents

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Types of Use

• Snuff (it replaced the pipe in England)

• Chewing tobacco

• Cigars (a combination of smoking and

chewing)

• Cigarettes

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SMOKELESS TOBACCO

There are different kinds of chewing tobacco, as

well as moist snuff = a small pinch is often placed

behind the lower lip.

Advantages:

-It is unlikely to cause lung cancer

-It is less expensive

Disadvantages:

-Increased risk of cancer in the mouth

-Carcinogens (nitrosammines) LEUKOPLAKIA

-Destructive effects on teeth by oral tobacco

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Nicotine

• It is a colorless, highly volatile natural substance in tobacco

• When smoked, nicotine enters the lungs and is then absorbed into the bloodstream

• When chewed, nicotine is absorbed through the mucus lining of the mouth

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MECHANISM OF ACTION

Nicotine mimics acetyl choline by

acting at nicotinic receptors.

http://www.youtube.com/watch?v=xzq160XvAK8

Nicotine also affects Dopamine &

releases adrenaline from adrenal glands

That increases: - dependence

- vasocostriction in the skin

- heart rate

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ACUTE TOXICITY

Only in the 1990s a tobacco manufacturer finally

admitted that cigarettes have seriously adverse

effects on health

Effects of low level nicotine:

1. nausea and general weackness.

2. Inhaling while smoking decreases hunger.

3. Carbon monoxide combines with hemoglobin in

the blood shortness of breath

In acute poisoning, nicotine causes tremors which

sometimes develop in convulsions.

The (rare) cause of death is suffocation resulting

from paralysis of the muscles used in respiration.

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CHRONIC TOXICITY

1. Smoking causes about 85% of all lung cancers

2. Smoking is related to 30% of premature deaths

per year (included Sudden Infant death

syndrome, SIDS)

3. Smoking causes 80 to 90% of deaths resulting from

chronic obstructive lung disease

4. Smokers have more chronic illnesses,

including: Emphysema & bronchitis

Cardiovascular disease

Cancer

Bronchopulmonary disease

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Smoking during pregnancy causes 2

times higher spontaneous abortions

and smaller head circumference, with

effects on the physical and intellectual

development of the child

CAUSES FOR CONCERN

Passive smoking:

the smoke from the ash of the

cigarette is higher in many

carcinogens than the one

delivered to the smoker’s

lungs.

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NICOTINE DEPENDENCE

Nicotine is the drug in tobacco that causes

addiction; it is the constituent in tobacco that

keeps smokers coming back for more– people

report no satisfaction if all the nicotine is removed.

Research has tried to develop “safer” cigarettes:

Nicotine replacement therapy and e-cigarettes

Nicotine affects dopamine, which reinforces the

dependence on nicotine

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NICOTINE REPLACEMENT THERAPY (NRT) Include administration of nicotine by means other than

tobacco. Examples: NICOTINE PATCHES (release of n.

through the skin), NASAL SPRAYS and NICOTINE

GUMS (which orally administers nicotine).

Pros: 1) prevention of the cravings in a smoker while

avoiding the toxic ingredients inside the common

cigarette.

2) easier overcoming of nicotine

addiction.

Cons: Patches may cause skin

irritation. Less satisfaction if the

physical activity of holding and puffing a cigarette is

removed.

Need for a combination of counseling and

pharmacological treatments.

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E-CIGARETTES

Pros: e-cigarettes may help in

smoking cessation and they

seem to be more effective than

traditional pharmacotherapy, as

Cons: The World Health Organization

(WHO) stated that the efficacy in using

electronic cigarettes to aid in smoking

cessation has not been proven

scientifically. No proper regulations. (July 2013)

the physical stimuli of holding and

puffing on the e-cigarette may be better

at improving short term craving.

http://www.youtube.com/watch?v=XvBVevkb5PU

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Tobacco

Nicotine

Psycho-

Therapeutics Prozac

Haloperidol

Opioids Morphine

Codeine

Heroin

Methadone

Depressants Barbiturates

Inhalants

Alcohol

Marijuana

Hallucinogens

LSD

Stimulants Cocaine

Amphetamine

Caffeine

Psycho-

active

Drugs

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Three drugs that come from cannabis:

marijuana,

hashish,

hash oil

Cannabis

The term “marijuana” refers to the leaves and flowering tops

of the cannabis plant that are dried to produce a tobacco-like

substance. Marijuana is usually smoked in the form of loosely

rolled cigarettes called joints, bongs (sometimes with PCP).

Joint or

bong or

blunt

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Hashish consists of the resinous material of the cannabis

plant, which is collected, dried, and then compressed into a

variety of forms, such as balls, cakes, or cookie-like sheets.

Pieces are then broken off, placed in pipes, and smoked.

In general hashish is stronger than marijuana.

Hash oil is produced by extracting the cannabinoids from

plant material with a solvent.

In terms of its psychoactive effect, a drop or two of this

liquid on a cigarette is equal to a single “joint” of

marijuana.

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The drugs obtained from cannabis are considered as

depressant, (opioid) narcotic and sometimes even

hallucinogen.

Cannabis plant contains more than 400 chemical substances.

About 60 of them are unique and are not found in any other

plant.

These substances are called cannabinoids. The substance

that is most responsible for the physical and psychic effects of

cannabis is THC (delta-9-tetrahydrocannabinol)

THC is the primary mind-altering

ingredient both in hashish and in

marijuana. Usually hashish has a higher

content of THC.

The structure suggests it is soluble in

fats, hence it tends to accumulate in the

body for long time.

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Pharmacology of THC in Marijuana or hashish

•When smoked, THC is rapidly absorbed (orally is slowly

absorbed) into the blood and first distributed to the brain,

then to the rest of the body.

•THC blood presence is about 19 hours, while 25-30% of

THC and its metabolites are still in the body after 1 week

•The high fats solubility determines a fast storage of THC

and its metabolites and a slow release.

•Urine testing: for THC metabolites (some tests are very

sensitive, so positive even for passive inhalation).

Limit: they do not indicate when marijuana was smoked and

which was the impairment of the individual at that time

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Mechanism of action

Cannabinoids modulate the availability of a variety of

neurotransmitters:

Acetyl choline

Norepinephrine

Dopamine

Serotonin http://learn.genetics.utah.edu/content/addiction/mouse/

through the interaction of THC with “cannabinoid”

receptors (CB1 and CB2) similarly to endogenous

molecules (Anandamide), which blocks inhibitory molecules and

thus allows the delivery of Dopamine

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Rapid effects of Marijuana/Hashish

Increase in Heart rate

Increased euphoria, elongation of events

Appetite stimulus (food kick) and an uncontrollable

fit of laughter (laugh kick)

Anticonvulsant activity- muscle relaxation Reduction of eye’s pressure in glaucoma

Reduction of nausea

Depend on: 1) concentration (Quality); 2)

Inhalation; 3) How long in the lungs; 4) Time

between 2 marijuana cigarettes

Intensification of the emotional situation you are in

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Chronic effects of Marijuana/hashish

•Tolerance may not develop uniformly:

Even SENSITIZATION!! (reverse tolerance)

•No obvious Physical dependence. Psychological

dependence in some marijuana smokers (other

drugs?)

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Acute Toxicity

•No human deaths have been reported from

overdose of cannabis

•Little evidence that drivers who use marijuana

are more likely involved in an accident (people’s

characteristics and internal events)

•Some panic reactions

•Abstinence syndrome: withdrawal effects within

12 hours, with hot flashes, irritability and

insomnia (milder effects than heroin or cocaine)

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• Respiratory effects: difficult to compare with

tobacco: - lower amount of marijuana cigarettes

- not filtered

1 marijuana cigarette corresponds to:

- 5 cigarettes for the amount of Carbon monoxide

- 4 cigarettes in terms of tar intake

- 10 cigarettes in terms of cell damage

Chronic Toxicity

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Chronic Toxicity (continues)

•Sexual functioning: in men it reduces

testosterone; in women it enhances chances of

abortion. Lower weight and shorter

muscle/skeletal length in newborns

• Cognitive effects: AMOTIVATIONAL SYNDROME

(diminished inspiration to participate in social situations

and activities), depression and loss of memory:

more in young people

http://www.videojug.com/interview/marijuana-side-effects-2#does-

marijuana-cause-depression

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Medical Uses

•In multiple sclerosis it provides relief since

cannabinoids have anti-inflammatory, muscle

relaxant properties

•Reduction in Nausea in patients taking anti-

cancer drugs (chemoteraphy)

•Treatment of appetite loss (AIDS)

•Asthmatic relief (dilates bronchioles in the

lungs)

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http://www.youtube.com/watch?v=IwNjFLPpnYA

Marijuana for medical use: not

for legalization, but to give

more options to patients and

medical doctors

http://www.ebaumsworld.com/video/watch/129068/

Marijuana Vending machines

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•Despite a lack of scientific evidence, in 1930s the

Federal Bureau of Narcotics (FBN) initiated an anti-

marijuana propaganda. Effects ranged from temporary

elation to the most violent of all sexual stimulants.

•Some movies in the 1930s and 1940s demonized the

substance (“demon weed”)

•The Marijuana Tax Act of 1937 was passed. It was a tax

law so it did not outlaw marijuana- just taxed it

•In 1942 some beneficial medical applications were

identified

CONTROVERSIES AND DEMONIZATION

History of marijuana

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1) Scientific American reported in 1939 that marijuana

when combined with intoxicants makes the user have

a desire to fight and kill. The problem was that there

was no medical evidence to support the relationship

between marijuana and crime

2) In the 1960s some articles in journals reported

misconceptions about the drug: study on 38

individuals showed 13 females exhibiting sexual

promiscuity. Due to female hormone estrogen in

marijuana?

3) An important factor is Amotivational Syndrome=

unwillingness to participte in normal social activities.

Symptom or cause?

REASONS FOR PROHIBITION

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4) Carcinogenic effects?

So why tobacco is allowed?

5) The predominant factor is as GATEWAY drug.

Those using marijuana are more likely to

switch to more dangerous drugs. 3 facts

support that: 1) evidence of progression 2)

results from heavy users 3) contact with “bad”

individuals.

Anyway, for the majority marijuana is a

“terminus” rather than a gateway

REASONS FOR PROHIBITION (continues)

http://www.youtube.com/watch?v=0GSRYnO1RSw

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IS PROHIBITION THE REAL SOLUTION?

CASE STUDY: THE NETHERLANDS

The Netherlands in 1976 allowed for sale and

use of marijuana in coffee shops

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IS PROHIBITION THE REAL SOLUTION?

CASE STUDY: THE NETHERLANDS (continues)

Illegal Drugs USA The

Netherlands

Marijuana 36.9 (16 y.o.) 17.0 (20 y.o.)

Cocaine 12.3 2.9

Ecstasy 3.6 2.9

LSD 9.0 1.0

Heroin 1.4 0.4 2001 National Household Survey

Explanations: 1) low rates of poverty in the Netherlands and

superior health care system

2) Success of Dutch in separating cannabis and hard drug

markets

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Marijuana: Trends in perceived availability, perceived risk of

regular use, and prevalence of use in the past 30 days for high

school students (USA)

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Legality of Cannabis in the world

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Penalties in Singapore

Possession or consumption of Cannabis:

Up to 10 years of imprisonment or S$20,000 fine or

BOTH

Illegal traffic, import or export of:

Cannabis of more than 500 grams > DEATH

Cannabis resin of more than 200 grams > DEATH

Cannabis mixture of more than 1,000 grams > DEATH

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PREVENTION AND TREATMENT OF

DRUGS OF ABUSE

Psychoactive drugs are not a recent phenomenon:

use/misuse/abuse can be traced back to the

historical origin of the humanity. But increased in the

last 50 years

BENEFIT-COST RATIO

Positive effects, that’s why drugs are taken

Negative effects: Tolerance

Dependence

Withdrawal effects

Toxicity

Ratio

deteriorates

Faster with

more

addictive

drugs

(cocaine)

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PREVENTION AND TREATMENT OF

DRUGS OF ABUSE Primary prevention: for young people, who

haven’t tried yet the substance in question or

just a few times

Useful, but also dangerous because there is the

risk of introducing new items…so increased

curiosity!!

Secondary prevention: for young people, who

have tried the substance in question. Useful to

avoid the use of others

Tertiary prevention: to avoid relapse. For

alcoholic, heroin and cocaine addicts

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Universal program: for the delivery to the entire

population

Selective program: for people at high risk (e.g.

students)

Indicated program: targeted at individuals who

show signs of developing problems

PROGRAMS

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Knowledge-Attitude-Behaviour Model: providing

information about drugs would increase knowledge

about their effects, determining changes in attitudes

about drugs and decreasing the drug-use behaviour.

Increased curiosity?

Depends on the purpose: to avoid or to make rational

decisions?

Social-Influence Model: e.g. smoking: presenting

information or videos about the dangerous

consequences of smoke is ineffective. Better teen

leaders. And adults? DARE (Drug Abuse Resistance

Education, by police officers).

Peer-Parents-Community Model: alcohol free parties,

field trips…learning with fun +trusting +not alone

WHERE and HOW?

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SINGAPORE

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Drugs alone only relieve the CORE symptoms

DRUG PLUS PSYCHOLOGICAL

THERAPY: the OPTIMAL

THERAPEUTIC PACKAGE

Psychological intervention alone might be

counterproductive, especially in those who are

susceptible to stress

Therapeutic drugs and psychological

intervention are both needed in order to achieve

the optimal outcome of complete social

integration